Locking device for track switches or the like



Aug. 18, 1953 H. R. SMITH 2,649,537

LOCKING DEVICE FOR TRACK SWITCHES QRITHE LIKE Filed April 16, 1948 4 Sheets-Sheet 1 IN V EN TOR.

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HIS flTTOIZZVEY Aug. 18, 1953 H. R. SMITH 2,649,537

LOCKING DEVICE FOR TRACK SWITCHES OR THE LIKE Filed April 16, 1 .948 4 Shees=$heet 2 UNLULK 22 .2

IN V ENTOR.

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H S ATTORIVKY Aug. 18, 1953 H. R. SMITH 2,649,537

LOCKING DEVICE FOR TRACK SWITCHES OR THE LIKE Filed April 16, 1948 4 Sheets-Sheet 4 INVENTOR. Happy '12. 512261512.

Patented Aug. 18, 1953 LOCKING DEVICE FOR TRACK SWITCHES OR THE LIKE Harry R. Smith, Wilkinsburg, Pa., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania Application April 16, 1948, Serial No. 21,443

8 Claims.

My invention relates to locking devices, and particularly to electric locks for preventing the unauthorized operation of outlying railway traffic controlling devices, such as track switches, derails, or the like.

In railway signaling and traffic controlling systems, such outlying track switches are moved by a hand-throw lever and electric locking devices are used to retain the lever in one of its extreme positions. These locking devices commonly include both padlocks and additional locks electrically controlled from a distant point. This additional electrical control prevents authorized persons provided with keys for opening the padlocks from releasing the locking mechanism to operate the switch unless conditions are proper for such operation. The distant electric control is imposed on the electric lock by means of an external control circuit which may be governed either by a manual control established by an operator of a remote control system, such as a centralized trafiic control system, or by an automatic control established by track circuits, positions of signals, etc., or by both manual and automatic controls. An electric lock of this type is shown in Letters Patent of the United States No. 2,387,115, granted October 16, 1945, to Herbert L. Bone, for Electric Lock.

Electric locks of the prior art, such as the one shown in the Bone patent previously referred to, have usually been provided with two pedals, one for releasing pressure on the padlock so that it could be removed, and another for releasing the switch lock itself. Such locks have also been provided with emergency release mechanisms by which an operator at the switch could release the lock without waiting for the electrical control circuit to be energized.

It is an object of my invention to provide an improved and simplified locking device of the type described.

Another object is to provide such a locking device for a railway track switch in which a single pedal is operated initially to permit removal of a padlock and then is moved additionally in the same direction to release the lock completely.

Another object is to provide an improved emergency release mechanism for a lock of the type described. A further object is to provide the emergency release with contacts which close a circuit to indicate at a remote point that the emergency release has been used.

Another object is to provide a lock of the type described with an improved indicator for informing a switchman that the device is elec= trically locked, sothat he will not make futile attempts to release the look when the electric lock is imposed.

I accomplish these objects by providing a locking device including a latch of conventional construction movable between locking and unlocking positions. The latch is biased by a spring to its extreme locking position. A single foot pedal is provided for moving the latch in opposition to the spring. Initial movement of the latch by the foot pedal releases a padlock so that the latter may be removed. Then the lock is released completely by a continuing movement of the pedal in the same direction. An electric lock operated by an electromagnet is provided to prevent movement of the pedal and latch to its released position unless a control circuit for the electromagnet is energized.

My emergency release mechanism is operated by a push button accessible through a hand hole closed by a cover which is padlocked. The push button mechanically releases the normally electrically operated locking mechanism and also closes a pair of electrical contacts which complete a circuit to indicate at a remote point that the emergency release has been used.

A signal lamp within the casing is electrically connected with the lock releasing electromagnet so as to be energized whenever the electromagnet is energized. The switchman is thereby advised whether manual release of the lock can be accomplished by means of the pedal.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form of electric lock embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is an elevational view of a switch operating mechanism provided with an electric lock embodying my invention. Fig. 2 is a plan view of the electric lock shown in Fig. 1, the cover of which has been removed to illustrate the parts. Fig. 3 is a sectional view of the electric lock shown in Fig. 1 taken substantially on the line IIIIII of Fig. 2. Fig. 4 is a sectional view of the electric lock shown in Fig. 1 taken substantially on the line IVIV of Fig. 2. Fig. 5 is a sectional view on a larger scale taken substantially on the line VV of Fig. 4. Fig. 6 is a view on an enlarged scale, partly in section on the line VI-VI of Fig. '7 and partly in elevation, of a portion of the electric lock shown in Fig. i. Fig. '7 is a sectional view of the portion of the electric lock of the mechanism B rests in a jaw 3 of thelook when the lever 2 occupies-itsnormal posi tion as shown. The switch operating mechanism. B may be of any desired construction so connected to the movable switch pointsthat the lever 2 controls the movement oftli'e points; but as here shown the mechanism 3 is of the type shown,

and described in Letters lEatent -of theUnited.

States No. 2,184,870, granted to Herbert L...Bone. and Kenneth J. J. McGowan on December 26'; 1939, for Railway SwitchOperating Mechanisms.

Referring now to the. remaining drawings; the electric look A is provided with an' upper casing fl and a lower casing ii. Casings 4i and 5 are bolted together by'means of elongated" through. bolts 6. Casing, l'is closed at its upper end .by'a removable cover 7. The cover l is apertured to. loosely receive a wingeheaded stud "lot by means of which the cover may be fastened down. This stud la is receivable ina tapped hole in a bracket 8, which is mounted on upper casing end walls la and db by tap bolts 9. The cover l is also provided with a staple Thin which. a padlock may be inserted so as to. interfere with rotation of the stud la and thereby lockthe cover in place. The lower casing-5 is provided with an extension tilt of which the jaw 3 is an integral part. The extension 5a is provided. onits front side with two. spaced vertical standards. Iii which support a pivot pin ll. Pivotally mounted.v on the. pin ll between the standards is a=lever latch lz movable between an extreme latching position. and an. extreme unlatching position. Lever latchv l2 isprovided with a noseportion IZaw-hich, when. the latch occupiesa latchingposition (as shown in Fig. 3), projects into the upper end of the jaw 3 in such manner thatit prevents movement of the lever 2 into or out of the jaw. When the latch I2 is moved to an unlatchingposition, noseportion l2a is withdrawn from the. jaw. The latch i2 is also. provided with a hole IZ-hso disposed that the bail it of a padlock-f (see Fig. 3) can be inserted throughthehole lZb When. the latch occupies the latching position. Notches a formed in the standards H3 are in'alignmentlwith hole lZb when the latch l2 isin. its'latching'position.

Pivotally mounted between the standards l0 below the latch l2 on another pin Hi is a foot pedal provided with a finger l5a which projects into and cooperates with a recess I in the lower edge of the latch [2 in such manner that counterclockwise movement of the foot pedal will cause clockwise movement of the latch. The foot pedal is is also provided with a depending portion i512 having slotted bifurcations which straddle the outer end of a rod IS. The rod l6 extends through the casing extension 5a below the jaw 3 and projects at its inner end into the lower casing 5. The foot pedal I5 is operatively connected with the rod l6 by a pin l1 extending through the slots in the bifurcated portion i517 and a clearance hole in the rod.

The rod is is slidably supported adjacent its inner end It?) in a grooved pedestal it formed ill attached to the sleeve it, such as by means of threads provided on the periphery of the sleeve Id; andthe other end of the spring 2i is sirni'larly attached to the nut 2E3. Sleeve t3 and nut- 29 are so adjusted that the spring 2! is under tension sufiicient to bias the foot pedal iii in a c'l'ockwise'direction, as viewed in Fig. 3, to an extreme raised'position in which a stop surface lee on the rear "edge oithe foot pedal engages a confronting.v stop surface its on the outer face of the jaw 3. The extreme right-hand positon to which the rod can be moved is limited by engagement of a shoulder 5511 with the outer end of the sleeve it;

When thefoot pedal i5 is in its extreme raised position as described above, the lever latch i2 isrotated counterclockwise from the position shown in Fig. 3, to its extreme latching position in which the noseportion l2a is fully-projected into jaw 3. In this extreme position of the latch 52 the hole 52b in the latch will have rotated past the notches its in the standards as to a position below the notches in which padlock bail I3 cannot be inserted in the hole. In order to padlock the lever latch 12, it is then necessary to depress the foot pedal If; a slight amount. When the foot pedal is moved to an extreme depressed position in which the shoulder ltd engages the sleeve E9, the latch i2 is rotated clockwise, as viewed in Fig. 3, to its extreme unlatching position in which nose portion are is out of the path of movement of the lever 2.

In the unlatching position just described, foot pedal finger its will have been rotated to a position in which. it is clear of an opening 22 (see Fig. 3) in one of the standards it. As best seen in l, the free end 23a of a lock rod is loosely supported to slide in the opening 22 The other end 23b of rod it is eccentrically pivoted to the hub of the hand-throw lever 22 so that when lever 2 is swung upwardly out of jaw 3, the rod will be moved to the right, as viewed in l, or forwardly as viewed in Fig. 3, blocking the finger Me. This action serves to retain the foot pedal E5 in its depressed position and the latch l2 in its unlatched position in opposition to the bias of the spring 2i. The lever latch l2 and foot pedal 15 are therefore held in their respective unlatched and depressed positions during movement of lever 2 and during the time the lever 22 occupies its reverse position. The return of the handthrow lever to its normal position in jaw 3 will cause movement of the rod 23 to the left, as viewed in Fig. l, to the position which the free end of the rod will have moved out from behind finger 55a, allowing the foot pedal 55 and the coacting lever latch 52 to rotate once more under the bias of spring 2i to their respective extreme raised and latching positions.

The portion of the locking device thus far described relates to means for applying padlock control to a spring-loaded lever latch. The looking device also comprises electrical means for at times locking the hand-throw lever in its normal position.

This electrical means includes an electromagnet the energization of which is controlled from a distant point over a control circuit. The control circuit forms no part of my present invention, and it is sufficient for present purposes to point out that this circuit controls the energization of the electromagnet in accordance with the desires of a remote operator or the condition of one or more signal circuits.

Referring again to the drawings, a gear 24 provided with toothed sectors in its upper and lower edges is pivotally mounted on a pin 25 so that its lower gear teeth mesh with a rack IBb provided on the upper surface of the inner end of rod l6. Pin 25 is supported in a bearing frame 26 secured to bosses in the lower casing 5 by tap bolts 2'! (see Fig. 3). Rotatably mounted above gear member 24 is a shaft 28. Shaft 23 is supported at one end in a bearing mounted in the end wall 4a of upper casing 4 and at its other end in a bearing 29a formed in a bracket 23 secured to a boss in the casing 4 by tap bolts 30 (see Fig. 6). Aifixed to the shaft 28 intermediate its ends is a sector gear 3| which meshes with the upper toothed. sector of a gear 24. It will be seen, therefore, that movement of rod [6 to the right, as viewed in Fig. 3, causes clockwise rotation of shaft 28. Y

Affixed to the left-hand end of shaft 28, as viewed in Fig. 4, to rotate therewith is an upstanding locking segment 32. The upper arcuate end of segment 32 is provided with a notch 32a (see Fig. 5) adapted for cooperation with a locking dog 33. The notch 32a is elongated to permit the segment to rock through a limited angle when the dog 33 is in a locking position within the notch. Attached to the top edge of segment 32 is a dog depressor bar 321) (see Fig. 5). Bar 321) overlies the notch 32a for a part of its length. A portion 320 of the bar is offset upwardly from and is concentric with the top edge of the segment 32.

As best seen in Fig. 4, locking dog 33 is substantially U-shaped. The lower leg 33a of the dog 33 extends into the notch 32a (see Fig. 5) and the upper or body portion 33b is disposed with clearance between confronting parallel surfaces 40 and 4d formed integrally with the upper casing end wall 4a. Dog 33 is pivotally suspended from the free end of one arm 34a of a bell crank lever 34, the other arm 34b of which has attached thereto, such as by tap screws 35, an armature 36. Lever 34 is bifurcated to straddle bracket 8, and is pivotally supported by trunnions 8a in the aforementioned bracket 8 through the medium of trunnion screws 3'! threaded in the lever 34 and secured by nuts 38 (see Fig. 3). Bracket 8 is longitudinally disposed beneath the arm 34a of lever 34 and extends with clearance through the lever opposite trunnions 8a. As previously noted, the bracket 8 is mounted at its ends on end walls 4a and 4b. It will be seen from Fig. 4 that the arm 34a of lever 34 is substantially horizontal while the arm 34b is substantially vertical. This causes the lever 34 to be biased in the counterclockwise direction, as viewed in Fig. 4, by the unbalanced weight of the arm 3411. It will also be seen from Fig. 5 that movement of dog 33. and hence rotation of lever 34 is permitted only when the dog 33 is between the notch 32a and the offset portion 320 of the depressor bar 321).

An electromagnet 4! is attached by threaded core bolts 39 and nuts 43 to a transverse depend ing portion 8b of the bracket 8. The other ends of core bolts 39 carry pole pieces 39a which attract the armature 36 when the electromagnet is energized. Attraction of the armature 36 by the electromagnet causes the lever 34 to be urged in a clockwise direction in opposition to its bias. Conversely, deenergization of the electromagnet releases the armature 35 so that lever 34 may rotate counterclockwise due to its bias.

The parts are so proportioned that lever latch I2 is in the padlocked latching position shown in Fig. 3 when looking segment 32 is positioned as shown in Fig. 5. Electromagnet 4! is then deenergized and dog 33 is biased downwardly into notch 32a. If a switchman then desires to release the lock, he first removes the padlock, and then depresses foot pedal 15. This rotates the segment 32 clockwise until the left-hand edge of the notch 32a, as viewed in Fig. 5, is brought into contact with the dog 33. In this position of segment 32, the lever latch I2 still does not permit the hand-throw lever 2 to be swung out of jaw 3. This condition exists when the padlock control of the lock is removed, but the distant electrical control has not been actuated to permit an unlocking of the switch operating mechanism. If, however, the condition of the distant electrical control is such that electromagnet 4| is energized, then dog 33 is moved upwardly out of notch 3211. Accordingly, the segment 32 then may be rotated clockwise by further depression of pedal 15 to an extreme unlocking position in which the dog 33 is positioned along the top edge of the segment just clear of the left-hand limits of the offset portion of bar 321). The lever latch i2 is then clear of jaw 3. Under these conditions the padlock has been removed and the distant electrical control has been actuated to permit an unlocking of the switch operating mechanism. By reason of the movement of the lock rod 23 into the path of pedal I5, segment 32 remains in its unlocking position so long as the hand-throw lever 2 is out of the jaw 3, and, during such time, th external control circuit may or may not be actuated to energize the electromagnet. When the lever 2 is returned to its normal position in jaw 3, the lever latch I2 is rotated under the action of the spring bias to its extreme latching position. Segment 32 is then rotated counterclockwise, as viewed in Fig. 5, to an extreme locking position. During this movement of segment 32, depressor bar 32b forces dog 33 downwardly into notch 32w. When the movement is completed, dog 33 just abuts the right-hand edge, as viewed in Fig. 5, of notch 32a. The dog returns to the position in the notch shown in Fig. 5 when foot pedal I5 is depressed slightly to insert the padlock bail l3.

If an attempt is made to operate the lock with electromagnet 4| deenergized, any force acting through segment 32 which tends to misalign or otherwise damage dog 33 and lever 34 is opposed by a reactive force upon engagement of the dog with the surface 40.

An important feature of my invention is embodied in the mechanism which forces dog 33 to its locking position in notch 32a when segment 32 is rotated counterclockwise by the spring bias. This mechanism includes the sloping right-hand end, as viewed in Fig. 5, of the offset portion 32c of depressor bar 32b. It is obvious that this feature is desirable in order to insure a positive break in the magnetic attraction of the armature 35 or to overcome a sticking of the movable parts.

A drum-type circuit controller 42 (see Fig. 4) is mounted on a portion of shaft 28 for rotation therewith. Another drum-type circuit controller 43 is rotatably mounted on another portion of aeeaasr shaft 28. Both controllers are provided with a plurality of contact bands 44 which cooperate with pairs of contact fingers 44a and 44b disposed on opposite sides of shaft 23 (see Fig. 3) and carrying circuit controlling contacts M0. The contact bands at are secured at their ends within longitudinal slots provided in the insulating drums of the controllers. Byassembling the bands in the, proper positions on the drums and by varying their lengths, the contacts Ma and 44b can be made to make or break a contact in any desired position of foot pedal l5. The contact fingers Ma and Mb are, secured by means of terminal posts 25 to an insulating terminal board 46, which, in turn, is; secured, by tap screws 4? to a boss formed integrally in upper casing 4. The upper ends of each pair of contact fingers Ma and 64b extend above theassociated drum controller: and are provided-with clearance holes through which thethreaded stud extensions of anv insulating bridging member 48 project. Nuts 19 screw onto the projecting; ends of the stud extensions andmay be tightened against the outer surfaces of the fingers to effect an urging of the finger ends together which, in turn, produces an increase-in contact pressure between the fingers and contact bands :34. Thus an adjustment of the contact pressure to any degree desired is obtained merely by tightening or loosening the nuts 4-9.

As best seen in Figs. 6-, '7 and, 8, the drum controller i3- is fixed on a spool 50' which is rotatable on the shaft, 23 and is driven by a lost-motion connection with the shaft and a toggle mechanism. One end-of the spool 5E3 is provided with an integral arcuate projection 50a partially encircling the shaft 28. A collar 51 secured to the shaft 28 for rotation therewith forms the journal for the shaft 28 in the bearing 29a, and is provided at one end with an integral arcuate projection 51a which engages: the} projection 50a.

The projections Ella and 5 in together donot com-- 54, and a knife-edge 55-which rides in a bearing 290 formed in a depending portion of bracket 29. Guide pin, 54 is pivoted on pin 52' and extends through spring 53 and knife-edgefifi- (see Fig. 6-).

As illustrated in. Figs. 6 and '7', the shaft 28 has rotated the controller 43" counterclockwise, L.-

through engagement oftheleft ends of projections 5m and Mia, as viewed in Fig. 8, to the position in which the depending portion 50b of the spool 56 is vertical. Further counterclockwise rotation of theshaft 28'wil1 cause thetoggle mechanism to go over center with a snap action and thereby rapidly throw the depending portion 5% to the right under the force of the, expanding spring 53'. This throw to-theright produces a quick-acting counterclockwise rotation of the drum controller 43 which is in the same direction as, but which, dueto. its rapidity, is relative to the rotation of the shaft 28. In like manner, clockwise rotation of shaft 28' rotates spool 56- clockwise through engagement of the right ends of projections Bio and 50a, as viewed in Fig. 8-, until the depending portion 50b is vertical, from which point a slight additional clockwise rotation of the shaft will cause a quick-acting clockwise rotation of th drum. controller relativev L3 to the shaft. Rotation of the controller 43 in either direction is limited by engagement of one or the other of two stop lugs 50c integrally formed on opposite sides of the spool 50 with one of two stops 2% integrally formed on the bracket 29.

It will thus be seen that by properly arranging the contact bands M- a positive and quick-acting completion and interruption of the circuits associated with controller 43 will be had during an operation of the lock.

As best seen in Fig. 4 the end wall 4b is' provided with a recess ie in its upper portion. Secured by tap screws 56 in an aperture in the recess la is a spring-loaded push button 57- for effecting an emergency unlock of the electrically controlled locking mechanism. Push button 51 is positioned in recess 4e directly opposite the armature 38 so that when the button is pressed inwardly an insulating plunger 57a is moved endwise to engage the depending leg of lever 34 and force the attached armature against the pole pieces eta. This causes the lever 34 to rock on trunnions Ba and urge the dog 33 out of notch 32a to effect an unlock of the normally electrical- 1y controlled locking mechanism. A feature of this emergency unlock means resides in the provision of spring metal contact fingers 58 and 59 which are adapted to engage contact points on opposite sides of plunger 57a when the push bu ton is in its normal unoperated position, but which fingers are out of engagement with the contact points when the plunger is moved endwise during an emergency unlock operation. The.- fingers 58' and 59 are attached to terminal posts be mounted on an insulating back plate of the push button, and the contact points are electrically connected through the plunger 51a to form a contact 5859. The contact 58-59 may be used as a circuit controlling contact in any suitable external circuit wherein an indication of the emergency unlock is desired. Access to push button 57' is afforded through a hand hole 7c in cover 7 which hand hole la is provided with a hinged water-tight cover 6| adapted to be padlocked by means of a standard hasp and eye tI-a.

Mounted in another aperture in the recess ie is an indication light 62, the lamp 62a of which is on the outer side of the recess so that when the light is energized, it is externally visible through a sight and vent tube 63 mounted in cover (it. The light 62 is provided for direct connection in the external control circuit to the electromagnet M by means of terminal wires 62b. It is therefore apparent that energization or. deenergization of the external control circuit to the electromagnet will at all times be indicated by the presence or absence, respectively, of the flow from lamp 62. Accordingly, the indication light fea-- ture enables a switchman to ascertain exactly when permission to operate the lock has been obtained from the distant electrical control and obviates the requirement inherent in older forms of electric switch locks of removing the pad- .lock and making possible several repeated attempts to operate the look.

A night service light 54 (see Fig. 2), the energization of which may be supplied from an external power source, is suitably attached, such as by bolts 65, to the inner side of the recess ie for facilitating the making of minor repairs and. adjustments to the lock during periods of darkness. Provisions may be made for energizing the light (it only during periods of usage or for con.- tinuously energizing the; light during cold weather to prevent formation of ice on the contacts.

A vent tube 66 (see Fig. 4) similar to sight and vent tube 63 is provided in the end of upper casing 4 opposite to that in which tube 63 is mounted to insure cross circulation of air over all heatproducing contacts and electromagnet surfaces. The lock is also provided with a standard type of support bracket 61 (see Fig. 4). The bracket 6"! is adapted to guide and support a well-known form of lock bar for insuring against movement of the switch points when the hand-throw lever 2 occupies its normal position. The usual form of lock bar is connected at its one end to the movable switch rails and provided at its other end with a recess for receiving the lever 2.

If it becomes necessary to repair any part of the electrical locking mechanism, the electrical operating unit comprising the casing 4 and the parts within it may be readily separated from the base unit which includes the casing 5. This separation is accomplished simply by removing the four through bolts 6. The lower teeth of gear 24 readily separate from the rack on rod lfib to permit separation of the two units. These gear teeth also readily engage each other when the operating unit is to be replaced. While the operating unit is removed, the latch 12 and padlock 13 are still effective to retain the switch operating lever 2 in its normal position.

Although I have herein shown and described only one form of an electric lock embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. An electric lock for railway track switches comprising a latch movable between a range of latching and unlatching positions, biasing means for moving said latch to its extreme latching position, a movable member for moving said latch to its unlatching position against said biasing means, a locking member movable with said movable member through a range of locking and unlocking positions, a locking dog cooperating with said locking member to prevent movement of said locking member and said movable member when said members are in their respective locking and latching positions, electromagnetic means including an armature connected to said locking dog and effective when energized to move said dog out of locking engagement with said locking member to permit movement of said movable member and said locking member, an electrical circuit controller including a set of contacts; a lost motion connection between said locking member and said contacts, a toggle connection between said locking member and said contacts, said connections permitting operation of the movable member a predetermined degree before operation of said set of contacts; and means for locking said movable member in an intermediate position against the bias of said biasing means, the controller contacts being inoperative when said movable member is in its intermediate locked position.

2. An electric lock for railway track switches comprising a latch movable between a range of latching and unlatching positions, biasing means for moving said latch to its extreme latching position, a movable member for moving said latch to its unlatching position against said biasing means, a locking member movable with said movable member through a range of locking and unlocking positions, a locking dog cooperating with said locking member movable between a first position for locking said locking member and a second position for unlocking said locking member, means on said locking member for biasing said locking dog to its first position to restrict movement of said member to its locking positions, electromagnetic means including an armature connected to said locking dog and eifective when energized to move said locking dog to its second position to permit movement of said movable member and said locking member, an electrical circuit controller including a set of contacts; a lost motion connection between said locking member and said contacts, a toggle connection beween said locking member and said contacts, said connections permitting operation of the movable member a predetermined degree before operation of said set of contacts; and means for locking said movable member in an intermediate position against the bias of said biasing means, the controller contacts being inoperative when said movable member is in its intermediate locked position.

3. A circuit controller comprising a rotatable shaft, two contact drums, one of contact drums being fixed on said shaft, a spool rotatable on said shaft and carrying the second drum, an arcuate projection on one end of said spool, a collar fixed on the shaft adjacent said one end of the spool, an arcuate projection on the collar extending toward the spool so as to engage the projection thereon when said shaft is rotated, said two projections occupying less than the entire shaft periphery so as to form a lost motion connection between said spool and said shaft, a toggle mechanism connecting the spool to a fixed connection so that when the shaft is rotated beyond a predetermined point in its travel the spool and its contact drum are moved by the toggle mechanism, and stationary contact fingers held in engagement with each of said contact drums.

4. A circuit controller comprising a rotatable shaft, a contact drum rotatably mounted on said shaft, a lost motion connection between said drum and said shaft including a projection on one end of said drum, a member fixed to said shaft adjacent said one end of said drum and a projection on said member extending toward said one end of said drum so as to engage the projection thereon when said shaft is rotated; a toggle mechanism connecting said drum to a fixed connection so that when said shaft is rotated beyond a predetermined point in its travel the contact drum is moved by the toggle mechanism, and stationary contacts held in engagement with said contact drum.

5. A circuit controller comprising a rotatable shaft, a contact drum rotatably mounted on said shaft, a lost motion connection between said contact drum and said shaft for rotating said drum, a toggle mechanism connecting said contact drum to a fixed connection so that when said shaft is rotated beyond the predetermined point in its travel the contact drum is rotated by said toggle mechanism, and stationary contacts held in engagement with said contact drum.

6. A circuit controller comprising a rotatable shaft, two contact drums, one of said contact drums being fixed on the shaft, a spool rotatable on said shaft and carrying the second drum, an arcuate projection on one end of said spool, a collar fixed on the shaft adjacent said one end of the spool, an arcuate projection on the collar extending toward the spool to engage the projection thereon when said shaft is rotated, both said projections occupying less than the entire shaft periphery to form a lost motion connection between said spool and said shaft; a toggle mechanism including an extendin portion on said spool, a stationary bearing, a knife edge riding on said bearing, a guide pin pivoted at one end to said extending spool portion and passing through said knife edge and bearing, and a spring interposed between said knife edge and said extendin spool portions whereby the spool and its contact drum is rotated when the shaft is rotated beyond a predetermined point in its travel; and stationary contact fingers held in engagement with each of said contact drums.

'7. A circuit controller comprising a rotatable shaft, a contact drum rotatably mounted on said shaft, a lost motion connection between said drum and said shaft including a projection on one end of said drum, a member fixed to said shaft adjacent said one end of said drum and a projection on said member extending toward said one end of said drum so as to engage the projection thereon when said shaft is rotated; at 2 12 stationary contacts held in engagement with said contact drum.

.8. A circuit controller comprising a rotatable shaft, a contact-drum rotatably mounted on said shaft, a lost motion connection between said contact drum and said shaft for rotatingsaid drum, .a toggle mechanism including an extending portion on said drum, a stationary bearing, a knife edge riding on said bearing, a guide pin passing through said knife edge and said bearing, and :a spring interposed between said knife edge and said extending portion whereby said contact drum is moved when the shaft is rotated beyond a predetermined point in its travel; and stationary contacts held in engagement with said contact drum.

HARRY B. SMITH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 604,782 Owen May-31, 1893 821,495 Howe May 22, 19.06

1,224,542 Henry May 1, 191'] 1,935,597 Koppitz Novr 14, 193.3 1,991,801 Greenfield Feb. 19, 1935 2,184,870 Bone et al. Dec. 26, 1 939 2,387,115 Bone Oct. 16, 1945 2,416,986 Field et al. Mar. 4, 1947 2,437,328 McWhirter et al. Mar. 9, 1948 2,565,773 Langdon Aug. 28, 1951 

